Various retrofit parts (for example, a substrate with an IC chip mounted thereon and a monitor) are generally attached to a housing of a mobile electric device according to use modes. When the housing is formed by a metal member, it is demanded that the housing has attachment portions for the retrofit parts. PTL 1 discloses a magnesium alloy structural member having a resin member serving as an attachment portion in an edge portion of a rolled sheet of a magnesium alloy. Specifically, in the magnesium alloy structural member, a through hole is provided in the rolled sheet of the magnesium alloy, the resin member is joined to cover an inner surface of the through hole, and the resin member extends to one surface and the other surface of the rolled sheet, so that the resin member is firmly joined to the rolled sheet. For example, this magnesium alloy structural member is manufactured by forming a through hole in a rolled sheet by punching, placing the rolled sheet having the through hole in a mold, and then performing insert molding with resin inserted in the mold.